The present invention relates to a method and apparatus for positioning original pictures onto a transparent sheet to be mounted to a picture cylinder of a picture reproducing machine such as a color scanner and a color facsimile.
In a conventional layout scanner or the like, in order to edit reproduction pictures, such as trimming, layout, enlargement, reduction, and so forth, of the reproduction pictures, original pictures are scanned photoelectrically to obtain color separation picture signals of primary colors, and then the color separation picture signals are stored in a memory. Then, the coordinates of the color separation picture signals read out of the memory are transformed depending on the specified layout data.
In this embodiment, when the scanning is carried out by 500 lines of pitches per one inch in X and Y directions and a finish size is about 20 inches.times.28 inches, the total picture data for four colors of cyan C, magenta M, yellow Y and black B amounts to 560.times.10.sup.6 picture elements. Now, when each picture element has 256 steps (8 bits) of gradation, the picture data for the finish size requires approximately 560 megabytes.
For storing such picture data, a large scale memory using a magnetic disc or a magnetic tape is required. Further, when the rotations of the coordinates or the chages of the reproduction scales of the reproduction pictures which are once stored in the memory by means of the picture data, because of a large amount of data, a very long time is required or a processing circuit of high cost for exclusive use is necessary.